promql: Extend testing framework to support native histograms
This includes both the internal testing framework as well as the rules unit test feature of promtool.
This also adds a bunch of basic tests. Many of the code level tests can now be converted to tests within the framework, and more tests can be added easily.
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Signed-off-by: Harold Dost <h.dost@criteo.com>
Signed-off-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>
Signed-off-by: Stephen Lang <stephen.lang@grafana.com>
Co-authored-by: Harold Dost <h.dost@criteo.com>
Co-authored-by: Stephen Lang <stephen.lang@grafana.com>
Co-authored-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>
Wiser coders than myself have come to the conclusion that a `switch`
statement is almost always superior to a statement that includes any
`else if`.
The exceptions that I have found in our codebase are just these two:
* The `if else` is followed by an additional statement before the next
condition (separated by a `;`).
* The whole thing is within a `for` loop and `break` statements are
used. In this case, using `switch` would require tagging the `for`
loop, which probably tips the balance.
Why are `switch` statements more readable?
For one, fewer curly braces. But more importantly, the conditions all
have the same alignment, so the whole thing follows the natural flow
of going down a list of conditions. With `else if`, in contrast, all
conditions but the first are "hidden" behind `} else if `, harder to
spot and (for no good reason) presented differently from the first
condition.
I'm sure the aforemention wise coders can list even more reasons.
In any case, I like it so much that I have found myself recommending
it in code reviews. I would like to make it a habit in our code base,
without making it a hard requirement that we would test on the CI. But
for that, there has to be a role model, so this commit eliminates all
`if else` occurrences, unless it is autogenerated code or fits one of
the exceptions above.
Signed-off-by: beorn7 <beorn@grafana.com>
We haven't updated golint-ci in our CI yet, but this commit prepares
for that.
There are a lot of new warnings, and it is mostly because the "revive"
linter got updated. I agree with most of the new warnings, mostly
around not naming unused function parameters (although it is justified
in some cases for documentation purposes – while things like mocks are
a good example where not naming the parameter is clearer).
I'm pretty upset about the "empty block" warning to include `for`
loops. It's such a common pattern to do something in the head of the
`for` loop and then have an empty block. There is still an open issue
about this: https://github.com/mgechev/revive/issues/810 I have
disabled "revive" altogether in files where empty blocks are used
excessively, and I have made the effort to add individual
`// nolint:revive` where empty blocks are used just once or twice.
It's borderline noisy, though, but let's go with it for now.
I should mention that none of the "empty block" warnings for `for`
loop bodies were legitimate.
Signed-off-by: beorn7 <beorn@grafana.com>
* Implement Pretty() function for AST nodes.
Signed-off-by: Harkishen-Singh <harkishensingh@hotmail.com>
This commit adds .Pretty() for all nodes of PromQL AST.
Each .Pretty() prettifies the node it belongs to, and under
no circustance, the parent or child node is touch/prettified.
Read more in the "Approach" part in `prettier.go`
* Refactor functions between printer.go & prettier.go
Signed-off-by: Harkishen-Singh <harkishensingh@hotmail.com>
This commit removes redundancy between printer.go and prettier.go
by taking out the common code into separate private functions.
* Add more unit tests for Prettier.
Signed-off-by: Harkishen-Singh <harkishensingh@hotmail.com>
* Add support for spliting function calls with 1 arg & unary expressions.
Signed-off-by: Harkishen-Singh <harkishensingh@hotmail.com>
This commit does 2 things:
1. It adds support to split function calls that have 1 arg and exceeds the max_characters_per_line
to multiple lines.
2. Splits Unary expressions that exceed the max_characters_per_line. This is done by formatting the child node
and then removing the prefix indent, which is already applied before the unary operator.
This commit adds `@ <timestamp>` modifier as per this design doc: https://docs.google.com/document/d/1uSbD3T2beM-iX4-Hp7V074bzBRiRNlqUdcWP6JTDQSs/edit.
An example query:
```
rate(process_cpu_seconds_total[1m])
and
topk(7, rate(process_cpu_seconds_total[1h] @ 1234))
```
which ranks based on last 1h rate and w.r.t. unix timestamp 1234 but actually plots the 1m rate.
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
